InnoDB Lock.md

// file: lock0lock.h

/** The lock system struct */
struct lock_sys_t{
	char		pad1[CACHE_LINE_SIZE];	/*!< padding to prevent other
						memory update hotspots from
						residing on the same memory
						cache line */
	LockMutex	mutex;			/*!< Mutex protecting the
						locks */
	hash_table_t*	rec_hash;		/*!< hash table of the record
						locks */
	hash_table_t*	prdt_hash;		/*!< hash table of the predicate
						lock */
	hash_table_t*	prdt_page_hash;		/*!< hash table of the page
						lock */

	char		pad2[CACHE_LINE_SIZE];	/*!< Padding */
	LockMutex	wait_mutex;		/*!< Mutex protecting the
						next two fields */
	srv_slot_t*	waiting_threads;	/*!< Array  of user threads
						suspended while waiting for
						locks within InnoDB, protected
						by the lock_sys->wait_mutex */
	srv_slot_t*	last_slot;		/*!< highest slot ever used
						in the waiting_threads array,
						protected by
						lock_sys->wait_mutex */
	ibool		rollback_complete;
						/*!< TRUE if rollback of all
						recovered transactions is
						complete. Protected by
						lock_sys->mutex */

	ulint		n_lock_max_wait_time;	/*!< Max wait time */

	os_event_t	timeout_event;		/*!< Set to the event that is
						created in the lock wait monitor
						thread. A value of 0 means the
						thread is not active */

	bool		timeout_thread_active;	/*!< True if the timeout thread
						is running */
};